1. Field
The invention relates to a lighting assembly including light emitting diodes as light source. In particular, the invention relating to an outdoor lighting device that can be used for an aircraft.
2. Description of the Related Art
An aircraft generally has several outdoor lighting devices for illuminating outdoor areas while the aircraft is in motion on the ground or in the air. An aircraft may include landing lights located on the wings and used to illuminate the landing runway when the aircraft is approaching the runway or during the take-off, a flashing anti-collision light mounted on the top of the rear spoiler, and navigation lights mounted on the tip of each wing. An aircraft may also include taxi type lighting devices mounted on the nose of the aircraft to illuminate the track on which the aircraft is travelling when he is moving on the ground, and additional lighting devices called “runway turn-off lights” (RTO).
The taxi type and runway turn-off type track lighting devices are intended to help the crew visualize the curves in the taxiways and runways towards the front and in the turns. The taxi lighting devices are generally mounted on the front landing gear and are intended to illuminate in front of the aircraft, while the runway turn-off lighting devices are generally mounted on the front landing gear or on the front of the wings and oriented on each side of the front of the aircraft with angles of between approximately 35° to 55° in order to illuminate the curves and thus improve the visibility while turning.
These track lighting devices must provide a relatively powerful beam over a distance of about 30 m in front the aircraft with a light beam extending laterally in a horizontal plane, i.e. relatively parallel to the wings plane taking into account the dihedral angle, but concentrated in a vertical plane, that is, relatively orthogonal to the wings of the aircraft taking into account the dihedral angle. Indeed, only the illumination of the track in a turn or curve is necessary.
The track lighting devices generally include as a light source an incandescent light bulb generating a light beam in every direction from the filament and a mirror redirecting a portion of the light beam forwardly. An incandescent light bulb may be very fragile when the filament is heated, reducing its lifetime. Moreover, the amount of electric power consumed for operating the filament and therefore emitting the light beam may be significant.